package com.hero.take.util;

/**
 * 坐标转换
 */
public class GpsUtil {

    static double pi = 3.14159265358979324;
    static double a = 6378245.0;
    static double ee = 0.00669342162296594323;
    public final static double x_pi = 3.14159265358979324 * 3000.0 / 180.0;


    /**
     * 计算两个GPS坐标点之间的距离，单位米
     * @param lat1 纬度1
     * @param lng1 经度1
     * @param lat2 纬度2
     * @param lng2 经度2
     * @return 距离 （米）
     */
    public static double distance(double lat1,double lng1,double lat2,double lng2){
        double radLat1 = Math.toRadians(lat1);
        double radLat2 = Math.toRadians(lat2);
        double a = radLat1 - radLat2;
        double b = Math.toRadians(lng1) - Math.toRadians(lng2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a/2),2) + Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b/2),2)));
        return Math.round(s * 6378137.0);
    }

    public static double distance(String lat1,String lng1,String lat2,String lng2){
        return distance(Double.parseDouble(lat1),Double.parseDouble(lng1),Double.parseDouble(lat2),Double.parseDouble(lng2));
    }


    public static void main(String[] args) {
        System.out.println(distance(30.748915,120.785012,30.752843,120.785076));
    }

    /**
     * wgs转百度
     * @param lat
     * @param lon
     * @return
     */
    public static double[] wgs2bd(double lat, double lon) {
        double[] wgs2gcj = wgs2gcj(lat, lon);
        double[] gcj2bd = gcj2bd(wgs2gcj[0], wgs2gcj[1]);
        return gcj2bd;
    }

    /**
     * gcj转百度
     * @param lat
     * @param lon
     * @return
     */
    public static double[] gcj2bd(double lat, double lon) {
        double x = lon, y = lat;
        double z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * x_pi);
        double theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * x_pi);
        double bd_lon = z * Math.cos(theta) + 0.0065;
        double bd_lat = z * Math.sin(theta) + 0.006;
        return new double[]{bd_lat, bd_lon};
    }

    /**
     * 百度转gcj
     * @param lat
     * @param lon
     * @return
     */
    public static double[] bd2gcj(double lat, double lon) {
        double x = lon - 0.0065, y = lat - 0.006;
        double z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * x_pi);
        double theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * x_pi);
        double gg_lon = z * Math.cos(theta);
        double gg_lat = z * Math.sin(theta);
        return new double[]{gg_lat, gg_lon};
    }

    /**
     * wgs转gcj
     * @param lat
     * @param lon
     * @return
     */
    public static double[] wgs2gcj(double lat, double lon) {
        double dLat = transformLat(lon - 105.0, lat - 35.0);
        double dLon = transformLon(lon - 105.0, lat - 35.0);
        double radLat = lat / 180.0 * pi;
        double magic = Math.sin(radLat);
        magic = 1 - ee * magic * magic;
        double sqrtMagic = Math.sqrt(magic);
        dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
        dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);
        double mgLat = lat + dLat;
        double mgLon = lon + dLon;
        double[] loc = {mgLat, mgLon};
        return loc;
    }

    private static double transformLat(double lat, double lon) {
        double ret = -100.0 + 2.0 * lat + 3.0 * lon + 0.2 * lon * lon + 0.1 * lat * lon + 0.2 * Math.sqrt(Math.abs(lat));
        ret += (20.0 * Math.sin(6.0 * lat * pi) + 20.0 * Math.sin(2.0 * lat * pi)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(lon * pi) + 40.0 * Math.sin(lon / 3.0 * pi)) * 2.0 / 3.0;
        ret += (160.0 * Math.sin(lon / 12.0 * pi) + 320 * Math.sin(lon * pi / 30.0)) * 2.0 / 3.0;
        return ret;
    }

    private static double transformLon(double lat, double lon) {
        double ret = 300.0 + lat + 2.0 * lon + 0.1 * lat * lat + 0.1 * lat * lon + 0.1 * Math.sqrt(Math.abs(lat));
        ret += (20.0 * Math.sin(6.0 * lat * pi) + 20.0 * Math.sin(2.0 * lat * pi)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(lat * pi) + 40.0 * Math.sin(lat / 3.0 * pi)) * 2.0 / 3.0;
        ret += (150.0 * Math.sin(lat / 12.0 * pi) + 300.0 * Math.sin(lat / 30.0 * pi)) * 2.0 / 3.0;
        return ret;
    }
}
